DER EE DE-5000 vs MESR-100 Accuracy

[The Electrician]

I measured some electrolytic capacitors with the DER EE DE-5000 and also a Fluke 179.  The DER, using the TL-21, seemed to read about 6% lower than the Fluke.  I did the calibration routines as shown on Pages 15-17 of the DER manual and the unit passed for both the open and short tests.  I haven't done a bunch of testing (either before or after the calibration routine) but after the calibration routine I found that the gap narrowed a bit.  For example, on a capacitor marked as 470uF I had a reading on the Fluke of 429uF (don't know at what frequency) and on the DER I had a reading of 418uF (at 100Hz).

Ran another test with a ceramic capacitor.  The Fluke says 108nF; the DER says 98nf at 100Hz, 94nF at 1kHz, and 89nF at 10kHz, and 77nF at 100kHZ.

Without something else to compare to kind of hard to say....

Have a look at this thread: https://www.eevblog.com/forum/testgear/about-capacitance-measurement-with-dvms/msg489690/#msg489690

As can be seen in that thread, the measured capacitance of an electrolytic (and also high-k ceramics) varies depending on the frequency at which the measurement is made.

DVMs don't measure capacitance in the same way as a proper LCR meter (which the DE-5000 is).  It isn't even possible to speak of the "frequency" at which a Fluke or other DVM makes its capacitance measurement because it doesn't use a "frequency" (a sine wave in other words) to make the measurement.

Manufacturers of electrolytic capacitors almost always measure the capacitance of their capacitors using a sine wave with a frequency of 120 Hz and an excitation of .5 VRMS.  This means that the best way to measure the capacitance of an electrolytic is to use the same method as the manufacturers do: 120 Hz sine wave excitation; this method is most likely to give the same value as the manufacturers specify.  Using a DVM is likely to give a value higher than would be obtained with the method used by the manufacturers, as I explain in the above thread.

This thread goes into some detail about capacitor impedance: https://www.eevblog.com/forum/projects/impedance-lcr-esr-meters/

[Chupacabras]

Have a look at this thread: https://www.eevblog.com/forum/testgear/about-capacitance-measurement-with-dvms/msg489690/#msg489690

Excellent thread. Thanks. Perfectly made explanation. 

[Electro Fan]

Likewise, thanks for the explanations and links.

If anyone has any good/very basic tutorial on reactance (capacitance, inductance, etc. - especially with references to antenna design) that is strong on concepts and not too deep with math, especially something with good illustrations, video, etc please feel free to post any suggestions.  Thx

[Ray.B]

Don't put a DC voltage bias on the DEE EE D-5000 meter, there is no input protection, and you would kill the poor thing.  It is not designed to have DC on it's inputs, the Electrolylics Caps don't need a bias.  The meter is not a DMM.  If you put a bias on the inputs, "YOU ARE DOING SO AT YOUR OWN RISK".  The input specifically says to discharge your Electrolylics Capacitors, you will brick your brand new meter, and there is NO WARRANTY.   Later Ray.B

[WhichEnt2]

Likewise, thanks for the explanations and links.

If anyone has any good/very basic tutorial on reactance (capacitance, inductance, etc. - especially with references to antenna design) that is strong on concepts and not too deep with math, especially something with good illustrations, video, etc please feel free to post any suggestions.  Thx

Did you already checked the Keysight Technologies Impedance Measurement Handbook? But in don't contain anything about antenna stuff.
http://literature.cdn.keysight.com/litweb/pdf/5950-3000.pdf

I am also happy with my DE-5000.
One important point is how to measure ESR of polarized capacitors:  The DE-5000 does not apply DC bias voltage to the device, which should affect its operation.  I am working on the design of an adapter that can apply battery bias, stealing the design from the old GR digibridge, but my lab is temporarily shut down for remodeling.

Can you please share your opinion for the Keysight 16065C External Bias Adapter schematic (attached)?
I would like to make a dc bias adapter based on that schematic for my XJW-01 lcr-meter.

[cdev]

If the Uni-T can be used to measure ESR in circuit, that is likely quite useful.

For somebody who is interested in RF and tuned circuits, the DE-5000 fills in a need - because it measures low inductances accurately, which otherwise would cost much more to fill.

As far as I know, its the best low cost instrument for measuring inductance. To get that capability in other hardware would cost a LOT more.

[cdev]

Thanks for the tip..

Quote from: _Wim_ on 2016-01-22, 15:29:56

To measure a cap ESR, you can also do this with a function generator and an RMS multi-meter. Connect on leg of the cap to the output of the function gen (in 50 ohms output mode), the other leg to ground. Use a sine signal no higher then 100mv or so (at the frequency you want to test at), and connect the multimeter parallel to the cap to measure the voltage. We now have a 50 ohms resistor (output function gen) in series with the ESR of the cap => voltage divider network. As you know the voltage across the cap (Vcap) and the voltage of the source (Vs), the ERS can be calculated as follows:

ESR = (Vcap * 50) / (Vs - Vcap)

Edit: thanks rich, I indeed made a mistake when I wrote deducted the formula on paper. Now corrected

[HoracioDos]

Hi

I found this video about the DE-5000 sometime ago when I was learning the basics about ESR meters. At 19:30 it shows how to measure an electrolytic capacitor correctly and compare the result againt a peaktech 3705 . Play the video at 1.25x or 1.50x speed.



Hope this can help.

[TimFox]

That -hp- circuit looks very like the one I am designing, but haven't gotten around to building.
I would use several polypropylene capacitors in parallel, instead of the two back-to-back electrolytics, since I have a large stock of them.
I like the protection circuit on the bias voltage connection.